1. Field of the Invention
The present invention relates to an antibiotic resin composition and more particularly to an antibiotic resin composition which comprises antibiotic zeolites and does not discolor with time.
2. Description of the Prior Art
Heretofore, there have been known such inorganic antibiotics as silver-supporting active carbon as disclosed in Japanese Patent Un-examined Publication (hereinafter referred to as "J.P. KOKAI") No. 49-61950 and such organic antibacterial or antifungus agents as N-(fluorodichloromethylthio)-phthalimide. However, in the former (inorganic antibiotics), silver ions rapidly leach out therefrom and, therefore, it is difficult to attain a sustained antibiotic effect.
On the other hand, some of the latter (organic antibacterial or antifungus agents) have no antibacterial effect on certian kinds of bacteria and molds (in other words, they are inferior in general-purpose utility with respect to bacteria and molds). Further, even those having heat resistance sometimes decompose at a temperature of 150 to 300.degree. C. This leads to reduction of antibacterial effect.
For the purpose of eliminating the aforementioned drawbacks associated with these conventional antibiotics, there have been developed so-called antibiotic zeolites which comprise an antibiotic component supported on zeolite, as disclosed in Japanese Patent Published for Opposition (hereunder referred to as "J.P. KOKOKU") No. 61-22977 and J.P. KOKAI No. 60-181002. Moreover, J.P. KOKAI No. 59-133235 discloses that such antibiotic zeolites are incorporated into a variety of resins to impart antibiotic properties thereto and the resultant resins can be widely used by forming them into antibiotic films, fibers, containers and the like.
However, such an antibiotic zeolite suffers from the disadvantage that it gradually discolors in the course of time. While this discoloration has no influence on the antibiotic effect of the antibiotic zeolite, products made using a resin in which such an antibiotic zeolite is incorporated sometimes discolor and this may, depending on the nature of the products, greatly reduce their commercial value.